Universal power input radio receiver



N 1951 J. LA VIA UNIVERSAL POWER INPUT RADIO RECEIVER Filed Oct. 3, 1946 I I l I I I I I I I I I L... 5 H 7% I. 3

INVENTOR. J05fPH 1/] WA.

ATTORNEY Patented Nov. 13, 1951 UNITED STATES PATENT OFFICE UNIVERSAL POWER INPUT RADIO RECEIVER Claims.

This invention relates to control devices for electrical elements such as vacuum tubes whereby they may be operated selectively on A. C. or D. C. circuits of various voltages by a mere change in a selective switch, and it has particular reference to radio receiver circuits.

In different parts of the world, commercial house current varies. There are generally four main types of current used for residences, viz, alternating and direct current having potentials of 110 v. and 220 v. Radio sets today are made mainly for 110 v. A. C.D. C. and 110 v. A. C. Where 220 v. current is supplied, it is necessary in order to use any of the above sets, to introduce appropriate resistance in the line to cut down the voltage.

It is desirable that radio sets be built which will be universal in that they may operate efficiently on any one of the above types of current.

It is, therefore, a primary object of this invention to provide a radio receiver which is operable universally on 110 v.-220 v. A. C.D. C., and which is efficient and economical in use.

It is a further object of the invention to provide a 110 v. A. C.D. C receiver with a step-up, step-down device, as for instance an autotransformer, to obtain the efiicient qualities of a straight A. C. receiver when operating on alternating current.

It is a further object to provide a simple arrangement whereby a radio set or other combination of electrical elements such as vacuum tube circuits, electronic devices and rectifying systems may be employed selectively in connection with any of a plurality of circuits of various voltages by merely setting a selector switch for the available current.

Further and more specific objects, features, and advantages will more clearly appear from a consideration of the specification hereinafter set forth especially when taken in connection with the accompanying drawings.

Briefly and generally speaking, the invention includes a tapped autotransformer disposed between the power circuit and the elements to be controlled.

More particularly, the invention includes a 110 v.-220 v. step-up, step-down device, as for instance an autotransformer disposed between the power circuit and the elements to be controlled with a selector switch manually operable to put alternating current across the entire autotransformer or across only part of it, or to entirely bypass the autotransformer when direct current is supplied.

In the drawings:

Fig. 1 is a diagrammatic illustration showing a fragment of a receiver and a circuit diagram of the control device as adapted for use with a v. A. C.D. C. and 220 v. A. C.D. C. receiver or similar apparatus.

Fig. 2 is a detail of a control knob for a selector switch used in the circuit.

Fig. 3 is a diagrammatic view showing modification of the circuit diagram shown in Fig. 1.

In Fig. 1, there is shown a circuit diagram of the control device as adapted for use with a 110 v. A. C.D. C. radio receiver or similar apparatus and in which is shown an electrical plug [0 connected to a line cord H, wires l2-l3, receiver switch l4, fuse l5, and selector It.

The selector l6 comprises a double pole switch having elements Il-I8 connected to conductors I 2l3 respectively, and a plurality of contacts a-a', bb', c and (1, contacts a and b bein connected by the jumper [9.

The contact a is connected by conductor 24 to the centre tap 20, of autotransformer 2|, which has windings 22-23. The external terminal of winding 22 is connected by wire 34 to contact a, connector 19, and contact b, of the switch It, The external terminal of winding 23 is connected to contact e, connector I9, and contact 1, of another selector switch I 6 Contact I) is connected by means of conductor 26, to the terminal of winding 23; the contact 0 is connected by wire 27, to the conductor 24 and from this juncture, through continuation wire 21, to contact g, of the switch 15a; contact at is connected by wire 28, to contact h, of the switch [6a and is further connected to resistor 33. The wire 28, from the resistor 33, is joined to the continuation wire 24 from the centre tap 29. The wire 24' is then connected to the primary side of the filament 29 of the tubes 3525, 50L6, 12SK'7, 12SA'7, and 12SQ7. All the filaments of the tubes are connected in series across the conductors 2%, I3, of the power line, and attached to the conductor I3, is the switch element It, of the selector switch 6.

The cathode 30, of the rectifier is connected by conductor 3 I, to a filter system comprising condensers 32, and field 33, of a speaker 34, and the filtered current is applied by means of the conductor 35, to the conventional net work of receiver 35.

The switch element Ila of switch |6a is at-- tached to conductor 32 which is connected to the plate 25, of the rectifier; the cathode 30 is con- 3 nected to wire 3I, which in turn is connected to the filter arrangement.

For operation on 110 v. A. C., the knob 31 of the selector switch (Fig. 2) is rotated to the first position and the current flows along conductor I2, switch member ll of the selector switch I6, the switch being rotated to contacts w-a; the current is carried through conductor 24 to the centre tap 23, of the autotransformer 2I, through a continuation of conductor 24, the filaments 29, of the vacuum tubes, and returns through the conductor I3, thus completing the filament circuit.

The switch member I8 being positioned at contact a, the current is conducted through the wire 34, to the lower external terminal of the windin 22, thus completing the circuit to this section of the autotransformer. An induced current in winding 23 is carried from the top external terminal to contact e of the selector switch IGa, having a single switch member Ila and contacts a, Lo and h. This switch, I6a is mounted on the common shaft of the switch I6, and the switch element Ila of the switch IGa is positioned to contact e. The current is then carried along conductor 32 to plate 25 of the rectifier 3525. The current in cathode 30 is carried through conductor 3|, and to the filter system as previously explained.

For operation of this modification on 220 v. A. C., the selector switch I 6 is rotated to contacts bb, and the current in conductor I2 is carried through switch element Il, contact 1), wire 26 to the external terminal of winding 23 of the autotransformer 2!. The current is also conducted to contact 6, of switch I6a, connector I9, to contact f and to switch element Ila, which was rotated simultaneously with switch members Il, I8 of switch I6.

The switch member I8 is positioned at contact b, and the current is conducted through connector I9, wire 341 to the lower external terminal of the winding 22, thus completing the circuit to the whole of the autotransformer.

The current is then carried through switch element Ila, wire 32 and to plate 25. The current in the cathode 30 iscarried through the wire 3| and filtered as previously explained.

At the juncture of conductor 26, and the terminal of the winding 23, the current is passed t ou the W di g to the centre tap 20, continuation wire 22, filaments 29, and returns through conductor I3, thus completing the filament circuit.

The current in passing through the winding 23 is stepped down, so that the potential across centre tap 2B and return conductor I3, is 110 volts.

On 110 v. D. C., the selector switch I6 is rotated to the next position and the plug II) (Fig. 1) is inserted for correct polarity, that is to say that the positive current will fiow through conductor I2, switch element I'I, contact 0, conductor 2l, which is joined to conductor 24, centre tap 26, of the autotransformer 2|, continuation wire 24, filaments 29, and returns through conductor I3, thus completing the filament circuit.

At the juncture of conductors 21, 24, current is conducted through a continuation of the wire 21, to contact g, of the switch I6a, switch element Ila, wire 32, and to the plate 25. The current from this point on is filtered as previously described.

011220 v. D. C., the selector switch is rotated to the last position to the right and the positive current is conducted through wire I2, switch element Il, contact d, wire 28, connecting wire 4 28' and to contact h, of the switch I 6a, switch element Ila, conductor 32, plate 25, and the current is filtered as previously stated.

Current is also carried through continuation of wire 28, a suitable resistor 33, wire 24, filaments 29, and returns through the conductor I3. The potential in passing through the resistor 33 is reduced to volts.

It will be noted that when the receiver is operated on 110 v. or 220 v. direct current, the autotransformer is entirely by-passed.

In Fig. 3, a modification of the invention is shown wherein a 110 v. A, C.-D. C. receiver may be used in conjunction with a 110 v.-220 v. autotransformer wherein conductor 3I2 is connected to the centre tap 329, of a 110 v.-220 v. autotransformer 32 I, having windings 322 and 323; the external terminals of the autotransformer 321, are connected by conductors 32 i, 328 to a double pole, double throw switch 3I9, having switch elements 3Il3I8, contacts 3a-3a',3b3b'; and the conductors 32 328 are connected to contacts 3a3a respectively.

The centre tap 323, is connected by means of the conductor 3I2-3 I 2, to contact 3b, and a continuation of conductor 3 I 2 is connected to the primary end of the filament 329, of the 3525 rectifier. The switch element 3 I l is connected by wire 326, to the plate 325; conductor 3I3' is connected to switch element 3E8 by wire 3E3 and continuation wire 3I3 is connected to the external end of the filament of the 12SQ'l vacuum tube (Figs. 1, 4.). This completes the heater or filament circuit of the receiver, as all the filaments of the tubes are in series. Th cathode 330 is connected by conductor 33! to the filter arrangement and network of the receiver (Fig. 1)

In operation on 110 v. alternating current, the receiver switch is closed and the current flows through conductor 3| 2, fuse 3I5, centre tap 320, wire 3I2, and to the double pole, double throw switch 3| 6, the continuation wire 3I2, to the filament 329, of the rectifier 3525, and the heater circuit of the vacuum tubes is completed through the return wire 3 I 3 (Figs. 1, 4)

When the selector switch SIS is closed to the left, the switch members 3Il3I8 are positioned at contacts aa, and current then fiows through conductor 3I2, fuse 3I5, and centre tap 32D, winding 322, conductor 328, contact 3a, switch element 3I8, wire 3I3 and returns through wire 3I3. An induced current in winding 323 is conducted through wire 32 3, contact 3a, switch element 3Il, wires 322' and is applied to the plate 325, of the 35Z5 tube. The current in the cathode 330, is then conducted by wire 33I to the filter arrangement, as previously stated (Fig. 1)

For operation on 110 v. D. C., the switch 3H5 is closed to the right, and positive current will flow through conductor 3I2, filaments 329 (Fig. 1) and returns through wire 3I3, thus completing the heatercircuit. The switch elements 3Il--3I8 are positioned at contacts 3b3b', and the positive current in wire 3I2 is conducted through wire 3I2, switch element 3Il, conductor 324', and to the plate 325, of the rectifier. The current in the cathode 339, is carried by conductor 33I, and filtered in the usual manner and applied to the network of the receiver 36 (Fig. 1)

It will be noted that when the receiver is operated on 110 v. or 220 v. direct current, the autotransformer is entirely by-passed.

From the foregoing description of the invention, it is noted that when the receiver is operated on 110 v. A. 0.. the radio serves as straight 5. alternating current receiver due to the fact that the line voltage which is applied across a portion of the autotransformer is stepped up to 220 v. and this voltage is applied to the rectifier and the output is then filtered in the usual manner.

When the receiver is operated on 220 v., either alterating current or direct current, the full volt-- age is applied to the rectifier and the output is then filtered. It is obvious that when the receiver is operated on any one of the above-mentioned currents, the radio will operate at a higher efficiency.

It is also to be noted while the receiver is equipped with an autotransformer, the results obtained are similar to a receiver having a transformer for operation on alterating current.

From the several descriptions disclosed herein, it is seen that the autotransformer steps up the applied 110 v. A. C. to 220 v., thus obtaining the full benefits of an alternating current receiver. The adaptability of the autotransformer in stepping down 220 v., from the power line to 110 v. for the filament circuit (Fig l), and at the same time applying the full line voltage to the rectifier, indicates the feasability of using such a device in a receiver.

Still, such a receiver has the feature of its utility on 110 v. direct current. As previously stated, when the receiver is operated on 110 v. or 220 v. direct current, the autotransformer is selectively by-passed or entirely isolated.

As is Well known, approximately ninety-five percent of the electric power generated in this country is alternating current and a large portion of the power abroad is of the same type, therefore a receiver possessing the interchanging feature, in the majority of the cases, has the advantages of an alternating current receiver, even though the set is equipped to operate on direct current also.

While the invention has been described in detail and with respect to the present preferred forms which the invention may assume, it is not to be limited to such details and forms since many changes and modifications may be made in the invention without departing from the spirit and scope of the invention in its broadest aspects. Hence, it is desired to cover any and all forms and modifications of the invention which may come within the language or scope of any one or more of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a radio receiver operable on alternating current or direct current, the combination of a 110 volt-220'volt step-up step-down device, a plurality of tubes the filaments of which are connected in series, manually selective switching means to connect the filaments of said tubes to a source of current, said switching means further adapted to selectively apply from a sole input alternating current across a portion of said device or the whole thereof, or to by-pass said device for operation of said receiver either on 110 volts or 220 volts direct current from said sole input.

2. In a radio receiver operable on alternating current or direct current, the combination of a 110 volt-220 volt autotransformer, a plurality of tubes the filaments of which are connected in series, a manually operable selector switch and a rectifier, said switch being adapted to connect 110 volts alternating current to the filaments of said tubes and to a portion of said transformer whereby to apply an induced current from said transformer to the rectifier, to a filter system and to the network of the receiver, and said switch being further adapted to by-pass said transformer for operation of said receiver on volts direct current.

3. In a radio receiver operable on alternating current or direct current, the combination of a 110 volt-220 volt autotransformer, of a plurality of tubes, the filaments of which are connected in series, switching means operable selectively to connect the filaments of said tubes through a sole input to a source of alternating current or to a source of direct'current, and to apply the alternating current from said input to the autotransformer for operation of the receiver on said current, or to by-pass said autotransformer for operation of the receiver on direct current from said input.

a. In a radio receiver operable on alternating current or direct current, the combination of a 110 volt-220 volt autotransformer, with a plurality of vacuum tubes the filaments of which are connected in series, manually selective unitary switching means and a plurality of circuits in association with a rectifier, said switching means adapted to selectively apply 110 volts alternating current to the filaments of the tubes and across a portion of said autotransformer or 220 volts alternating current across the whole thereof and 110 volts alternating current from a portion of said autotransformer to the filaments oi the tubes and the current from the whole of th autotran former to said rectifier, a filter systern to smooth the output current from said rectifier, and means to connect said current to the network of the receiver, said unitary switching means further adapted to selectively by-pass the autotransformer and apply direct current to the filaments and rectifier for operation of the receiver on said direct current.

5. The combination with an alternating current or direct current radio receiver having a plurality of vacuum tubes the filaments of which are connected in series, manually selective unitary switching means and a plurality of associated circuits adapted to selectively apply 110 volts alternating current to the filaments of said tubes and a section of a 110 volt-220 volt autotransformer, and means to conduct an induced current from the autotransformer to a rectifier, a filter arrangement to smooth the rectified current and means to apply the filtered current to the network of the receiver, said unitary switching means further adapted to selectively by-pass the autotransf-ormer to apply direct current to the filaments, rectifier, filter and net work of the receiver for operation on said direct current.

6. The combination with an alternating current or direct current radio receiver, having a plurality of vacuum tubes the filaments of which are connected in series, manually selective unitary switching means and a plurality of associated circuits in association with a 110 volt-220 v-olt autotransformer and a rectifier, said unitary switching means and circuits adapted to selectively apply current to the filaments of the tubes and to a portion of said autotransformer or across the whole thereof, and to the rectifier for operation of the receiver on 110 volts or 220 volts alternating current, said unitary switching means further adapted to by-pass the autotransformer, apply direct current to the filaments and selectively conduct 110 volts or 220 volts direct current to the rectifier for operation of the receiver on one of said currents, a filter arrangement to smooth the output current from the rectifier and means to apply said filtered current to the network of the receiver.

7. In a radio receiver operable on alternating current or direct current having a plurality of electron discharge devices, each device having at least a filament and a power input electrode, a power supply circuit therefor comprising a pair of input terminals for connection to a current source, a transforming device having high and low voltage input and output means, a unitary manual switching means, a rectifier, and filtering means, said filtering means connecting the output of said rectifier to said power input electrodes, said switching means in a first position connecting said pair of input terminals to said low voltage input means, said low voltage output means to said filaments, and said high voltage output means to said rectifier input, said switching means in a second position connecting said pair of input terminals to said high voltage input means, said low voltage output means to said filaments, and said high voltage output means to said rectifier input, said switching means in a third position connecting said pair of input terminals to said filaments and to said rectifier input, and said switching means in a fourth position connecting said pair of input terminals to said rectifier input and through a voltage reducing element to said filaments.

8. In a radio receiver operable on alternating current or direct current having a plurality of electron discharge devices, each device having at least a filament and a power input electrode, a power supply circuit therefor comprising a pair of input terminals for connection to a current source,

a transforming device having high and low voltage input and output means, manual switching means, a rectifier and filtering means, said filtering means connecting the rectifier output to said power input electrodes, said switching means having at least four positions, two of said positions serving to connect said low voltage output means to said filaments and said high voltage output means to said rectifier input and to selectively connect said pairof input terminals to said low and high voltage input means, the other two of said positions serving to by-pass said transforming device and to connect said rectifier and filaments in parallel and to said pair of input terminals, one of said latter two positions connecting a voltage reducing device in series with said filaments.

9. A power supply circuit for a universal radio receiver comprising a pair of power input means, a pair of output leads for connection to the filaments of the receiver discharge devices, a rectifier having two elements, a filter connecting one of said rectifier elements to an output terminal for connection to the power input electrodes of said discharge devices, a transformer device having high, low and zero voltage input and output terminals, and manually operative switching means comprising first, second, and third movable elements associated respectively with a first, second and third group of selectable contacts, said first movable element being connected to one of said pair of power input means. said other one of said pair of power input means being connected to said second movable element and to one of said pair of output leads, said third movable element being connected to the second rectifier element, said first group of contacts having a first contact connected to said low voltage input terminal, a second contact connected to said high voltage input terminal, a third contact connected to said first contact, and a fourth contact connected through a resistor to said low voltage output terminal, said second group of contacts having two contacts connected to said zero voltage input terminal, said third group of contacts having two contacts connected to said high voltage output terminal, a third contact connected to said low voltage input terminal and a fourth contact connected to the end of said resistor remote from said low voltage output terminal, the other one of said pair of output leads being connected to said low voltage output terminal.

10. A power supply circuit as set forth in claim 9 wherein said movable elements are ganged on a common shaft and arranged for common movement into simultaneous contact with either said first, second, third, or fourth contacts of said groups.

JOSEPH LA VIA.

REFERENCES CITED The following references are or record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,036,343 Lyons Apr. 7, 1936 2,130,441 Wohlfarth et a1. Sept. 20, 1938 2,269,989 Root Jan. 13, 1942 2,281,488 Freeland Apr. 28, 1942 2,330,500 Leifer Sept. 28, 1943 2,439,409 Mitchell Apr. 13, 1948 

